Zn^(2+)与Cr^(6+)对水车前毒害的协同效应

Zn^(2+) and Cr^(6+) Synergetic Toxic Effects on Ottelia alismoides

比较研究了水体中单一Cr6+及外施Zn2+后对水车前抗氧化酶系统(SOD、POD、CAT)和叶绿素含量的影响,以探讨金属元素联合作用机理。结果表明:单一Cr6+处理下,1 mg·L-1处理浓度可产生一定的积极刺激作用, 表现为提高了SOD、POD和CAT活性和增加了叶绿素含量。与单一Cr6+处理相比,施加不同浓度的Zn2+后都不同程度地削弱了保护酶活性,叶绿素含量下降的幅度也更明显。这表明Zn2+的加入,削弱了水车前保护酶系统的保护作用,使水车前对Cr6+胁迫的耐性减弱,协同作用的趋势显著。

The effects of Cr^2＋ and its combination with Zn^2＋ on the antioxidative enzymes （SOD,POD and CAT） and chlorophyll content Ottelia alismoides were examined in waters to explore the synergetic action mechanism of heavy metals. The results revealed that the treatment with only Cr^2＋ at 1 mg· L^-1 could produce positive simulating effect in increasing then SOD,POD and CAT activities and the chlorophyll content. Compared with the treatment with only Cr^2＋ the treatments combined Cr^2＋ with Zn at different concentration can weaken the positive effect to a varying degree and remarkably lower the chlorophyll content. This indicated that the Zn^2＋ addition weakened the protective effects of the protective enzymes,so that O. alismoides reduced its tolerance to Cr^6＋ and increase the synergetic effects remarkably.